Kites ________ messages in the war in the past.
The meeting ___________ because of the smog in Northern China last week.— Oh, it’s too bad! We should take action to improve the air quality.
We should leave the classroom ____ the light____.
This box is ______ heavy ________ I can’tcarry it.
What the doctors really doubt is ____ my mother will recover from the serious disease soon[ ]